Metal blanks, such as sheet metal, often arrive at a manufacturing facility with a coating of mill oil on them which protects the blanks from corrosion and inhibits rust. Various contaminants like dust, dirt, and other particles may find their way onto the blanks and may become stuck in the mill oil or otherwise stuck on the blanks. Prior to forming the blanks into a desired product, the blanks are often cleaned to remove the contaminants and often the mill oil. This often includes passing the blanks through a wash station that may include brushes, rollers, wipers and the like, as well as water and cleaning solvents or detergents, if desired. Visual inspection of the washed blanks can be difficult and contaminants that remain on the blanks may result in larger imperfections when the blank is drawn, stamped or otherwise formed. These imperfections can render the part unusable or require time consuming, manual and often expensive repairs to the part.
Further, the existence of a defect does not necessarily mean the wash station did not perform properly because contaminants can find their way onto the blanks after the blanks are washed. Thus, it is difficult to determine if the wash station is operating correctly and if not, what the problem is. This often leads to more parts being formed with defects before the existence of a problem is identified and then the problem is determined.